Rocking arm circular saws are known in the art, as evidenced by U.S. Pat. No. 4,336,733 issued June 29, 1982, to Macksoud. The saw shown in this prior patent is of a bench or tabletop type construction which allows both cross cutting and ripping operations to be performed. The circular saw blade and associated driving motor therefor are both mounted on a rocking arm which is pivotally supported on the base of the saw, beneath a tabletop-like, horizontal surface which supports the workpiece to be cut. A generally U-shaped handle connected to the rocking arm assembly extends above the tabletop and provides the saw operator with a handle for rocking the saw blade from a lowered, retracted position beneath the tabletop to a raised cutting position in which at least a portion of the blade extends through a slot in the tabletop, above the tabletop surface.
Crosscutting operations are performed by maintaining the workpiece stationary on the tabletop and rocking the saw blade from its lowered retracted position to its raised cutting position, thereby pulling the blade through the workpiece to effect the cut. In order to perform ripping operations, the blade is rocked upwardly to a raised position at a desired cutting blade height and is locked in place, following which the handle is removed in order to eliminate it as an obstruction above the tabletop. The workpiece is then pushed across the tabletop and through the exposed portion of the saw blade in order to effect the cut.
Although the rocking arm saw described above is highly effective in operation and simple to use, the exposed portion of the saw blade above the tabletop presents some risk to the saw operator, even when caution is exercised. Heretofore, however, a safety device for guarding the saw blade has not been provided.
A number of problems must be dealt with in providing a saw blade guard for the type of rocking arm saw described above. For example, the blade guard must be effective in covering the blade during both crosscutting and ripping operations. During the crosscutting operation, however, the blade moves longitudinally along the path of the cut due to its rocking motion, thus it is necessary to provide a guard which tracks with the blade throughout its longitudinal displacement. Moreover, the guard should preferably allow retraction of the blade, even though the guard encounters an obstruction during the course of its return travel.
On the other hand, the guard must be mounted in a manner so as to cover the blade at all times during ripping operations but yet not present an obstruction to the path of travel of the workpiece and also not interfere when the saw is being employed in crosscutting operations. Additionally, for purposes of ripping operations, the guard must be positioned over the blade regardless of the longitudinal position of the blade which, as previously indicated, depends upon the blade cutting height that has been selected.
Each of the foregoing design problems must be dealt with while at the same time, consideration must be given to the ease and portability of the saw. The saw described in U.S. Pat. No. 4,336,733 mentioned above is lightweight, compact and may be quickly converted into a readily portable package, consequently it is necessary that the safety device for the blade be compatible with the portability of the saw and the ease with which it may be set up and taken down.
It is thus a primary object of the present invention to provide a safety device for a rocking arm saw which satisfies each of the requirements mentioned above.
Another object of the invention is to provide a safety device as mentioned above which is relatively simple, lightweight and easy to install.
Other objects will be made clear or will become apparent during the course of the following description of a preferred embodiment of the present invention.